The present invention releates to a novel 3-aryl-2-hydroxypropionic acid derivative, to a process and intermediate for preparing such a compound, having the utility in clinical conditions associated with insulin resistance, to methods for its therapeutic use and to pharmaceutical compositions containing it.
Insulin resistance, defined as reduced sensitivity to the actions of insulin in the whole body or individual tissues such as skeletal muscle, myocardium, fat and liver prevail in many individuals with or without diabetes mellitus. The insulin resistance syndrome, IRS, refers to a cluster of manifestations including insulin resistance with accompanying hyperinsulinemia, possibly non insulin dependent diabetes mellitus (NIDDM); arterial hypertension; central (visceral) obesity; dyslipidemia observed as deranged lipoprotein levels typically characterized by elevated VLDL (very low density lipoproteins) and reduced HDL (high density lipoproteins) concentrations and reduced fibrinolysis.
Recent epidemiological research has documented that individuals with insulin resistance run a greatly increased risk of cardiovascular morbidity and mortality, notably suffering from myocardial infarction and stroke. In non-insulin dependent diabetes mellitus these atherosclerosis related conditions cause up to 80% of all deaths.
In clinical medicine there is at present only limited awareness of the need to increase the insulin sensitivity in IRS and thus to correct the dyslipidemia which is considered to cause the accelerated progress of atherosclerosis.
Furthermore there is at present no pharmacotherapy available to adequately correct the metabolic derangements associated with IRS. To date, the treatment of NIDDM has been focused on correction of the deranged control of carbohydrate metabolism associated with the disease. Stimulation of endogenous insulin secretion by means of secretagogues, like sulphonylureas, and if necessary administration of exogenous insulin are methods frequently used to normalize blood sugar but that will, if anything, further enhance insulin resistance and will not correct the other manifestations of IRS or reduce cardiovascular morbidity and mortality. In addition such treatment involves a significant risk of hypoglycemia with associated complications.
Other therapeutic strategies have focused on aberrations in glucose metabolism or absorption, including biguanides, such as methformin, or glucosidase inhibitors, such as acarbose. Although these agents have been efficacious to a degree, their limited clinical effect is associated with side effects.
A novel therapeutic strategy involves the use of insulin sensitizing agents, such as the thiazolidinediones, which, at least in part, mediate their effects via an agonistic action on nuclear receptors. Ciglitazone is the prototype in this class. In animal models of IRS these compounds seem to correct insulin resistance and the associated hypertriglyceridaemia and hyperinsulinemia, as well as hyperglycemia in diabetes, by improving insulin sensitivity via an effect on lipid transport and handling, leading to enhanced insulin action in skeletal muscle, liver and adipose tissue.
Ciglitazone as well as later described thiazolidinediones in clinical development either have been discontinued reportedly due to unacceptable toxicity or show inadequate potency. Therefore there is a need for new and better compounds with insulin sensitizing properties.
Compounds of the formula 
and certain derivatives thereof disclosed in U.S. Pat. No. 5,306,726 and WO 91/19702 are said to be useful as hypoglycemic and hypocholesterolemic agents, and in U.S. Pat. No. 5,232,945 said to be useful in the treatment of hypertension.
AU 650 429 discloses structurally related compounds, but claimed to have different properties: diuretic, antihypertensive, platelet anti-aggregating and anti-lipoxygenase properties.
EP 139 421 discloses compounds having the ability to lower blood lipid and blood sugar levels. Among these compounds is troglitazone, a compound that has reached the market for treatment of NIDDM or decreased glucose tolerance.
It has now surprisingly been found that the novel compound 3-{4-[2-(4-tert-Butoxycarbonylaminophenyl)ethoxy]phenyl}-(S)-2-ethoxy propanoic acid having the formula I 
is effective in conditions associated with insulin resistance.
The invention also relates to pharmaceutically acceptable salts, solvates, such as hydrates, and crystalline forms of the compound of the formula I.
In the present specification the expression xe2x80x9cpharmaceutically acceptable saltsxe2x80x9d is intended to define but is not limited to such salts as the alkali metal salts (e.g. sodium, lithium and potassium), alkaline earth metal salts (e.g. calcium, barium and magnesium), aluminum, zinc and bismuth salts, ammonium salts, salts with basic amino acids, such as arginine, lysine, and salts with organic amines such as ethanolamine, ethylenediamine, triethanoleamine, benzylphenethylamine, diethylamine, tromethamine, benzathine, chloroprocaine, choline, meglumine, procaine, clemizole and piperazine.
Throughout the specification and the appended claims, a given chemical formula or name shall encompass all pharmaceutically acceptable salts thereof, crystalline forms and solvates thereof such as for instance hydrates.
Methods of Preparation
The compound of the invention may be prepared as outlined below according to any of methods A-H. However, the invention is not limited to these methods, the compound may also be prepared as described for structurally related compounds in the prior art.
A. The compound of the formula I of the invention can be prepared by converting a compound of formula II 
wherein A is xe2x80x94ORp, wherein Rp is a protective group, e.g. ethyl, or A is a chiral auxiliary group, such as a chiral amine, e.g. (R)-phenylglycinol, a chiral alcohol, such as menthol or a chiral oxazolidinone, such as (S)-4-benzyl-2-oxazolidinone. The convertion can be performed as a hydrolysis which can be either acidic or basic and performed according to standard methods known to anyone skilled in the art or as described in the experimental part.
B. The compound of the formula I or the formula II wherein A is a chiral auxiliary group or xe2x80x94ORp and Rp is as defined above, can be prepared by reacting a compound of the formula III 
wherein X is xe2x80x94OH or a leaving group such as a sulfonate or a halogen, with a compound of the formula IV 
wherein Q is H and A is a chiral auxiliary group, xe2x80x94OH or xe2x80x94ORp, and Rp is as defined above. The reaction can be performed either by an alkylation reaction or a Mitsunobu reaction.
In an alkylation reaction the leaving group X can be a sulfonate such as mesylate, nosylate, tosylate, or a halogen, such as bromine or iodine. The compounds of formula III and IV, in approximately equimolar amounts or with an excess of either compound, are heated to reflux temperature in an inert solvent, such as isopropanol or acetonitrile, in the presence of a base, such as potassium carbonate or cesium carbonate.
The mixture is refluxed for the necessary time, typically between 0.5 h to 24 h, the work-up procedure usually includes filtration, for removal of solid salt, evaporation, neutralization (when A=xe2x80x94OH) and extraction with water and an organic solvent such as dichloromethane, ethyl acetate, or diethyl ether. The crude product is purified if desired e.g. by recrystallization or by standard chromatographic methods.
The Mitsunobu reaction can be carried out according to standard methods or as described in for example Tsunoda T., Yamamiaya Y., Ito S., Tetrahedron Letters, 34, 1639-1642 (1993) or O. Mitsunobu, Synthesis, 1981, p.1. When using a Mitsunobu reaction A can not be xe2x80x94OH.
In a typical Mitsunobu reaction a compound of formula III, wherein the group X is a hydroxyl group, and a compound of formula IV are mixed, in approximately equimolar amounts or with an excess of either compound, in an inert solvent, such as chloroform, dichloromethane, or tetrahydrofran. A slight molar excess, 1-4 equivalents, of an azodicarboxylate, such as DEAD or ADDP and a phosphine (14 equivalents), such as tributylphosphine or triphenylphosphine are added and the reaction is stirred at a temperature high enoughxe2x80x94for example room temperaturexe2x80x94and a time long enough (1-24 hours) to obtain product, which can be worked up with standard literature methods and if desired purified, e.g. by standard chromatographic methods.
The compound of formula III can be prepared by standard procedures known to anyone skilled in the art, from commercially available staring materials or as described in the experimental section.
The compound of formula IV wherein Q is H and A is a chiral auxiliary group, xe2x80x94OH or xe2x80x94ORp, wherein Rp is as defined above, can be prepared as described below in the experimental part, or by converting a compound of formula IV 
wherein Q is Rq, wherein Rq is a protective group, e.g. benzyl, and A is a chiral auxiliary group, xe2x80x94OH or xe2x80x94ORp, wherein Rp is as defined above.
C. The compound of formula II, wherein A is a chiral auxiliary group, and the compound of formula IV, wherein A is a chiral auxiliary group and Q is hydrogen or Rq, wherein Rq is as defined above and, can be prepared by diastereoisomeric separation of the compound of the formula V 
wherein A is a chiral auxiliary group, Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above. The separation of the diastereomers can be performed either by crystallization or by chromatography. The chromatographic separation can be performed as described in the experimental part.
The compound of formula V wherein A is a chiral auxiliary group, Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, can be prepared by converting a compound of formula VI 
wherein Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq and Rx is hydrogen or Rp, wherein Rq and Rp are as defined above, for example by reacting it with a chiral amine or a chiral alcohol.
The compound of formula V when A is a chiral amine can be prepared by reacting a compound of formula VI with a chiral amine such as (R)-phenyl glycinol for example in the presence of a peptide coupling system (e.g. EDC, DCC, HBTU, TBTU, PyBop or oxalylchloride in DMF), an appropriate base (e.g. pyridine, DMAP, TEA or DIPEA) and a suitable organic solvent (e.g. dichloromethane, acetonitrile or DMF) in accordance with methods well known to those skilled in the art or as described in the examples.
The compound of formula V when A is a chiral alcohol can be prepared in the same way using a chiral alcohol, such as menthol, instead of a chiral amine, or by the mixed-anhydride method with pivaloyl chloride and the lithium salt of the chiral alcohol.
The compound of formula V wherein A is a chiral auxiliary group and Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, and the compound of formula VI, wherein Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq and Rx is hydrogen or Rp, wherein Rq and Rp are as defined above, can be prepared by reduction of a compound of formula VII 
wherein A is a chiral auxiliary group, xe2x80x94OH, or xe2x80x94ORp, wherein Rp is as defined above and Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, and if desired followed by removal of protecting groups.
The reduction of the olefin may be carried out using a wide variety of reducing methods known to reduce carbon-carbon double bonds, such as catalytic hydrogenation in the presence of an appropriate catalyst, or hydrogen transfer reagents such as diethyl-2,5-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate.
The catalytic hydrogenation can be performed in alcohol, cellosolves, protic polar organic solvents, ethers, lower aliphatic acids, and particularly in methanol, ethanol, methoxyethanol, dimethylformamide, tetralydrofuran, dioxane, dimetoxyethane, ethyl acetate or acetic acid either used alone or in mixture. Examples of the catalysts used include palladium black, palladium on charcoal, platinum oxide or Wilkinson""s catalyst. This reaction can be preformed at different temperatures and pressures depending on the reactivity of the aimed reaction.
In case of hydrogen transfer reaction with diethyl-2,5-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate the reaction can be conducted by mixing equimolar amounts of reactants and warming the mixture to melting (140-250xc2x0 C.) under inert atmosphere or under vacuum.
The compound of formula VII wherein A is a chiral auxiliary group, xe2x80x94OH, or xe2x80x94ORp, wherein Rp is as defined above and Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, can be prepared by a condensation reaction, such as a Knoevenagel or Wittig type reaction, of a carbonyl compound of the formula VIII 
wherein Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, with a compound of the formula IX 
in which formula A is a chiral auxiliary group, xe2x80x94OH, xe2x80x94ORp, wherein Rp is as defined above, or the formula X 
in which A is a chiral auxiliary group, or xe2x80x94ORp, wherein Rp is as defined above, L1xe2x95x90L2xe2x95x90L3 are phenyl or L1xe2x95x90L2 are Oalkyl and L3 is=O, and, if desired, followed by removal of protecting groups, by an arylation reaction as described in for example Cacchi S., Ciattini P. G., Morera E., Ortar G., Tetrthedron Letters, 28 (28) 1987, pp 3039-3042.
In the condensation step, approximately equimolar amounts of reactants are mixed in the presence of a base, to provide the olefin compound. This step may be carried out in the presence of an inert solvent or in the absence of a solvent at a temperature between xe2x88x9220xc2x0 C. and the melting point for the mixture. It might be necessary to add a dehydrating agent in order to obtain the olefinic compound.
In a typical such reaction the compounds of formula VIII and formula IX are mixed in a solvent such as tetrahydrofuran. Anhydrous potassium tert-butoxide is slowly added at low temperature i.e. xe2x88x9220xc2x0 C. The reaction is quenched with acetic acid. The crude product is isolated, redissolved in toluene and refluxed with p-toluenesulfonic acid in a Dean-Stark apparatus. The solution is cooled and the product is isolated and purified according to standard methods (see Groger T., Waldmann E., Monatsh Chem 89, 1958, p 370).
The condensation step could also be performed as a Wittig-type reaction (see for example Comprehensive Organic Synthesis vol. 1 p. 755-781 Pergamon Press) or as described in the experimental part.
In a typical such reaction, approximately equimolar amounts of reactants of formula VIII and formula X, are stirred in the presence of a base such as tetramethylguanidine or potassium carbonate in a 1-5 fold molar excess. This step may be carried out in the presence of an inert solvent such as dichloromethane or acetonitrile and at a suitable temperature (xe2x88x9210xc2x0 C.+60xc2x0 C.) for a sufficient time.
The compound of the formula VIII when Q is xe2x80x94CH2CH2Ph-4-NHCOOtBu can be prepared by coupling a compound of the formula III wherein X is xe2x80x94OH or a leaving group such as a sulfonate or a halogen, with a compound of the formula XI 
When X is a leaving group such as a sulfonate or a halogen, the reaction may be performed as an alkylation reaction and when X is xe2x80x94OH, as a Mitsunobu reaction as described above.
D. The compound of formula I or formula II wherein A is xe2x80x94ORp and Rp is as defined above and the compound of formula IV wherein A is xe2x80x94OH or xe2x80x94ORp and Q is H or Rq, wherein Rp and Rq are as defined above can be prepared by enantiomeric separation, such as chiral chromatography of the compound of the formula V 
wherein A is xe2x80x94OH or xe2x80x94ORp, Q is H, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq wherein Rp and Rq are as defined above.
E. The compound of the formula I or the formula II wherein A is a chiral auxiliary group, or xe2x80x94ORp, wherein Rp is as defined above, and the compound of formula IV wherein A is a chiral auxiliary group, xe2x80x94OH, or xe2x80x94ORp, wherein Rp is as defined above and Q is hydrogen or Rq, wherein Rq is as defined above, can be prepared by asymmetric reduction of a compound of the formula VII 
wherein A is a chiral auxiliary group, xe2x80x94OH, or xe2x80x94ORp, wherein Rp is as defined above and Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above. The asymmetric reduction can be carried out using a wide variety of reducing methods which are known to reduce carbon-carbon double bonds such as catalytic hydrogenation in the presence of an appropriate chiral catalyst such as Rh-BINAP or [Et-DuPHOS-Rh(COD)] or catalytic hydrogenation with an appropriate catalyst, such as palladium on charcoal using the chiral auxiliary group to induce the asymmetry.
The catalytic hydrogenation can be carried out in a wide variety of solvents, such as alcohol, cellosolves, protic polar organic solvents, ethers, lower aliphatic acids, and particularly in methanol, ethanol, methoxyethanol, dimethylformamide, tetrahydrofuran, dioxane, dimetoxyethane, ethyl acetate or acetic acid, either used alone or in a mixture. The reaction can proceed at different temperatures and pressures depending on the reactivity of the aimed reaction.
F. The compound of the formula I or the formula II, wherein A is a chiral auxiliary group, or xe2x80x94ORp, wherein Rp is as defined above, and the compound of formula IV wherein A is a chiral auxiliary group, xe2x80x94OH, or xe2x80x94ORp, wherein Rp is as defined above and Q is hydrogen or Rq, wherein Rq is as defined above, can be prepared by converting a compound of the formula XII 
wherein A is a chiral auxiliary group, xe2x80x94OH, or xe2x80x94ORp, wherein Rp is as defined above, and Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, with the required stereochemistry, dependent on the reaction conditions used.
The reaction may be carried out as an alkylation reaction, using a variety of alkylating agents, such as ethyl halide or diethyl sulfate (see for example Benedict D. R., Bianchi T. A., Cate L. A., Synthesis (1979), pp. 428-429, Barluenga J., Alonso-Cires L., Campos P. J., Asensio G., Synthesis, 1983, p. 53-55, Bull Chem Soc Jpn, 1986, 59, 2481, S. Patai, The Chemistry of the Ether Linkage, Wiley-Interscience NY, 1967, 445-498 or Survey of Organic Synthesis vol 1, Wiley-Interscience 1970, NY, p. 285-328).
The compound of formula XII wherein A is a chiral auxiliary group, xe2x80x94OH, or xe2x80x94ORp, wherein Rp is as defined above, and Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, can be prepared by asymmetric reduction of a compound of the formula XIII 
wherein A is a chiral auxiliary group, xe2x80x94OH, or xe2x80x94ORp, wherein Rp is as defined above, and Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above.
The asymmetric reduction may be performed by using a wide variety of reducing methods which are known to reduce ketones enantioselectively (see Flynn G. A., Beight D. W., Tetrahedron Letters, 29(4), 1988, pp. 423-426).
The compound of formula XII wherein A is a chiral auxiliary group and Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, may also be prepared by induced chiral reduction of a compound of formula XIII, wherein A is a chiral auxiliary group and Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above (see Xiang Y. B., Snow K., Belley M., J. Org. Chem., 1993, 58, pp 993-994).
The compound of formula XII, wherein A is a chiral auxiliary group, xe2x80x94OH or xe2x80x94ORp, wherein Rp is as defined above, and Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, can be prepared by converting a compound of the formula XIV 
wherein A is a chiral auxiliary group, xe2x80x94OH or xe2x80x94ORp, wherein Rp is as defined above, and Q is hydrogen, xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, with the required stereochemistry, dependent on the reaction conditions used ( see for example K. Koga, C. C. Wu and S. Yamada, Tetrahedron Letters, no. 25, 1971, p 2283-2286, Kunz H., Lerchen H-G., Tetredronjetters, 28 (17)1987, pp.1873-1876).
G. The compound of formula II, wherein A is a chiral auxiliary group, and the compound of formula IV wherein A is a chiral auxiliary group and Q is Rq, wherein Rq is as defined above, can be prepared by reacting a compound of formula XV 
wherein X is a leaving group, such as a halogen or a sulfonate, and Q is xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, with a compound of the formula IX 
wherein A is a chiral auxiliary group.
In the alkylation step the compound of formula XV is reacted with a compound of formula IX in the presence of one or more bases such as potassium carbonate, triethylbenzylammonium chloride, sodium hydride, LDA, butyllithium or LHMDS in a reaction inert solvent such as acetonitrile, DMF or dichloromethane at a suitable temperature and time. The reaction can be carried out using standard methods known in the literature: (see for example Pearsson W. H., Cheng M. C., J. Org. Chem., 51 (19) 1986, 3746-3748, Myers A. G., Yang B. H., Gleason J. L., J. Am. Chem. Soc. 1994, 116, pp 9361-9362, Negrete G. R., Konopelski J. P., Tetrahedron Assymetry, 2, 2, pp. 105-108, 1991, Davies S. G., Sanganee H. J., Tetredron Assymetry, 6, 3, pp. 671-674, 1995, Hulin B., Newton L. S., Lewis D. M., Genereux P. E., Gibbs E. M., Clark D. A. J. Med.Chem. 39, 3897-3907 (1996) and Savignac M., Durand J-O, Genet J-P, Tetrahedron Assymetry, 5, 4, pp.717-722, 1994).
The compound of formula XV wherein X is a leaving group, such as a halogen or a sulfonate, and Q is xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, can be prepared from a compound of formula XVI 
wherein Q is xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, using standard methods known to anyone skilled in the art.
The compound of formula XVI wherein Q is xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, can be prepared by reduction of a compound of formula VIII, wherein Q is xe2x80x94CH2CH2Ph-4-NHCOOtBu or Rq, wherein Rq is as defined above, by standard methods known to anyone skilled in the art.
H. The compound of the invention of formula I and the compound of formula IV, wherein A is xe2x80x94OH and Q is hydrogen or Rq, wherein Rq is as defined above, can be prepared by resolution of the racemate thereof and, if desired, followed by neutralization. The resolution can be performed by separative crystallization of a salt consisting of the racemate of, either the compound of the invention of formula I, or the compound of formula IV, and a chiral base, such as quinine, in an inert solvent such as ethyl acetate or toluene (see for example Duhamel P., Duhamel L., Danvy D., Plaquevent J. C., Giros B., Gros C., Schwartz J. C., Lecomte J. M., U.S. Pat. No 5,136,076, Stephani R., Cesare V., J. Chem. Ed., 10, 1997, p. 1226 and Yamamoto M., Hayashi M., Masaki M., Nohira H., Tetrahedron Assymetry, 2, 6, pp. 403-406, 1991).
The compounds of the invention may be isolated from their reaction mixtures using conventional techniques.
Persons skilled in the art will appreciate that, in order to obtain the compounds of the invention in an alternative and in some occasions, more convenient manner, the individual process steps mentioned hereinbefore may be performed in different order, and/or the individual reactions may be performed at different stages in the overall route (i.e. chemical transformations may be preformed upon different intermediates to those associated hereinbefore with a particular reaction).
In any of the preceeding methods of preparation A-H, where necessary, hydroxy, amino or other reactive groups may be protected using a protecting group, Rp or Rq as described in the standard text xe2x80x9cProtective groups in Organic Synthesisxe2x80x9d, 2nd Edition (1991) by Greene and Wuts. The protecting group Rp or Rq may also be a resin, such as Wang resin or 2-chlorotrityl chloride resin. The protection and deprotection of functional groups may take place before or after any of the reaction steps described hereinbefore. Protecting groups may be removed in accordance to techniques which are well known to those skilled in the art.
The expression xe2x80x9cinert solventxe2x80x9d refers to a solvent which does not react with the starting materials, reagents, intermediates or products in a manner which adversely affects the yield of the desired product.
Unless otherwise stated or indicated the term chiral auxiliary group denotes a chiral group, such as a chiral alcohol or amine, for instance (xe2x88x92)-menthol, (+)-isomenthol, (xe2x88x92)nomeol, (R)-2-phenyl glycinol, (S)-2-phenyl glycinol, (R)-4-phenyl-2-oxazolidinone or (S)-4-benzyl-2-oxazolidinone, which chiral group when connected to a carbonyl group can easily be cleaved to the corresponding acid.
Intermediates
a) When preparing the compound of the formula I of the invention an intermediate of the formula IV 
wherein Q is hydrogen and A is xe2x80x94OH or xe2x80x94ORp, wherein Rp is a protective group, e.g. ethyl, or A is a chiral auxiliary group, such as a chiral amine, e.g. (R)-phenylglycinol, or a chiral alcohol such as menthol or a chiral oxazolidinone, such as (S)-4-benzyl-2-oxazolidinone, is particularly useful. It is prepared as described above. Under the same heading its use as intermediate for the preparation of the end compound of the invention is described.
b) When preparing the compound of the formula I of the invention an intermediate of the formula III 
wherein X is xe2x80x94OH or a leaving group, such as a sulfonate or a halogen, is particularly useful. It is prepared as described above. Under the same heading its use as intermediate for the preparation of the end product of the invention is described.
Pharmaceutical Preparations
The compound of the invention will normally be administered via the oral, parenteral, intravenous, buccal, rectal, vaginal, transdermal and/or nasal route and/or via inhalation, in the form of pharmaceutical preparations comprising the active ingredient either as a free acid, or a pharmaceutical acceptable organic or inorganic base addition salt, in a pharmaceutically acceptable dosage form. Depending upon the disorder and patient to be treated and the route of administration, the compositions may be administered at varying doses.
The compound of the invention may also be combined with other therapeutic agents which are useful in the treatment of disorders associated with the development and progress of atherosclerosis such as hypertension, hyperlipidemias, dyslipidemias, diabetes and obesity.
Suitable daily doses of the compound of the invention in therapeutical treatment of humans are about 0.005-5 mg/kg body weight, preferably 0.01-0.5 mg/kg body weight.
According to a further aspect of the invention there is thus provided a pharmaceutical formulation including the compound of the invention, or pharmaceutically acceptable derivatives thereof, in optional admixture with pharmaceutically acceptable adjuvants, diluents and/or carriers.
Pharmacological Properties
The present compound of formula (I) will be adapted for prophylaxis and/or treatment of clinical conditions associated with reduced sensitivity to insulin (insulin resistance) and associated metabolic disorders. These clinical conditions will include, but will not be limited to, abdominal obesity, arterial hypertension, hyperinsulinaemia, hyperglycaemia (non insulin dependent diabetes mellitus (NIDDM)) and the dyslipidaemia (plasma lipoprotein disturbances) characteristically appearing with insulin resistance. This dyslipidaemia, also known as the atherogenic lipoprotein profile of phenotype B, is characterised by moderately elevated non-esterified fatty acids, elevated very low density lipoproteins (VLDL) triglycerides, low high density lipoproteins (HDL) cholesterol and the presence of small, dense, low density lipoproteins (LDL). Treatment with the present compound is expected to lower the cardiovascular morbidity and mortality associated with atherosclerosis. These cardiovascular disease conditions include macro-angiophathies causing myocardial infarction, cerebrovascular disease and peripheral arterial insufficiency of the lower extremities. Because of its insulin sensitizing effect the compound of formula (I) is also expected to reduce the progress of clinical conditions associated with chronic hyperglycaemia in diabetes like the micro-angiopathies causing renal disease and retinal damage. Furthermore the compound may be useful in treatment of various conditions outside the cardiovascular system associated with insulin resistance like the polycystic ovarian syndrome. The compound of the invention is a non-toxic insulin sensitizing agent with surprisingly good therapeutic effect and pharmacokinetic properties and without undesirable weight gain.
General Experimental Procedures
1H NMR and 13C NMR measurements were performed on a BRUKER ACP 300 and Varian UNITY plus 400 and 500 spectrometers, operating at 1H frequencies of 300, 400 and 500 MHz respectively, and at 13C frequencies of 75, 100 and 125 MHz respectively.
Unless otherwise stated, chemical shifts are given in ppm with the solvent as internal standard.